1. Field of the Invention
This invention relates generally to electrical circuit continuity testers and in particular to a novel continuity tester for use with electrode catheters.
2. Description of the Prior Art
An electrode catheter is a medical instrument designed to be inserted into a blood vessel or other body part, which is used for electrical stimulation or for the recording of electrophysiological information. A typical electrode catheter consists of a central core of wires which terminate at one end with one or more electrode rings. The end of the electrode catheter having the electrode rings is designed to be inserted into the blood vessel or other body part. The central core of wires which make up the electrode catheter terminate at the other end with a pin plug or other electrical connector which can be attached to an electronic instrument for pacing or for recording electrophysiological information.
The electrode catheter is a small and expensive device which is very fragile. As a result of its fragile nature, the catheter can be damaged prior to use or between uses. Because of the trauma associated with the catheter's insertion into a blood vessel, one should only use the device when reasonably assured that it is in working condition. For this reason, the manufacturers of electrode catheters recommend that a new catheter be used only once and then discarded because, at present, there is no convenient way to assure that the catheter is in working condition before use.
In addition, electrode catheters are expensive. It is therefore apparent that the ability to make multiple use of the catheters would result in substantial cost savings. Thus, there is a need for a device which provides a means to perform a convenient electrical continuity test for electrode catheters so that their functionality can be assured prior to use. This would allow the catheter to be re-used on multiple occasions.
Circuit continuity testers are generally known in the prior art. Such testers are used to establish whether or not circuit continuity exists between probe points in a circuit or terminals of a conductor or cable. Such testers normally employ a source of potential in series with the test probes and an instrument such as a lamp or a meter for determining proper electrical conductivity between the probe points.
Illustrative is U.S. Pat. No. 4,005,362 issued to Fortino which describes a typical electrical circuit continuity tester of simple construction. The continuity tester employs a light bulb, a cylindrical tube, batteries and 2 contacts which serve as probes for determining the continuity of a circuit. While such a device and others like it are extremely simple in nature, they do not provide a suitable means to make a quick and practical electrical connection with the electrode rings of the electrode catheter.
For cable testing, it is known to combine a continuity tester with appropriate connectors designed to mate with the terminating connectors of the cables to be tested. However, such arrangements are not practically suitable for making electrical contact with catheter electrodes because good contact must be made to the electrode rings without incurring any damage to the electrode rings or adjacent insulating materials. They also fail to meet the special requirements often attending medical environments.